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Antique Voyager Technology

Posted by kdawson on from the spinning-tapes-and-flashing-lights dept.

sea_stuart writes with a story from the Tidbinbilla space tracking station, outside Canberra, Australia. It is still communicating with the two Voyager spacecraft 30 years after they were launched and 18 years after Voyager 2 passed close by Neptune. Here's a little background on Voyager 1 and Voyager 2. "The bank of computers that would look at home in black-and-white episodes of Doctor Who cannot be junked... [T]he 1970s hardware is now our world's only means of chatting with two robot pioneers exploring the solar system's outer limits. Today Voyager 1 is humanity's most remote object, 15.5 billion kilometers from the sun. Voyager 2 is 12.5 billion kilometers from it. Both continue beaming home reports, but now they are space-age antiques. 'The Voyager technology is so outmoded,' said Tidbinbilla's spokesman, Glen Nagle, 'we have had to maintain heritage equipment to talk to them.'"

28 of 293 comments (clear)

  1. I've got an old dell they can use... by DragonTHC · · Score: 5, Insightful

    Is it really that impossible to run these machines inside an emulator on a modern server?

    I can still play my atari 2600 games on my xbox.

    --
    They're using their grammar skills there.
    1. Re:I've got an old dell they can use... by QMalcolm · · Score: 4, Insightful

      This is a total guess, but I'd think that just communicating with something like Voyager 1 would rely on lots of funky old hardware. I mean, the thing is 15 BILLION kilometers away, it's not quite the same as dumping a 2600 cart.

    2. Re:I've got an old dell they can use... by Anonymous Coward · · Score: 4, Insightful

      and yet I don't think it would be a problem for modern software or hardware.
      I think he was thinking more about analog components like amplifiers or something which might be unusual. It's not always all just bits.

      That said, I think the real reason isn't that it's not possible to duplicate with modern technology (it is, of course; anything we could have built then, we can build now), it's just that producing a new system just to communicate with Voyager would probably cost more than maintaining what we've got now. Especially since any new system would likely have unforeseen bugs in it, which could possibly result in loss of communication with the space craft (imagine accidentally sending a command which orders the Voyagers to point their radio antennas away from Earth).

      Still, it's a bit like the ridiculous argument that some day we won't be able to read CD-ROMs, because the technology will have advanced so far, the hardware will no longer exist. Well, yes, maybe. But scientists will always be able to build something that can scan the surface of a CD-ROM, and decode the data there. But it might not be very economical (though I doubt it; a binary infrared laser scanning device is pretty dirt simple). There's a big difference there between what's economically and technologically unfeasible.
    3. Re:I've got an old dell they can use... by arth1 · · Score: 5, Insightful

      The problem isn't that a new computer can't emulate the software, it's more that it (a) can't do it out of the box and (b) can't emulate the hardware. If you, say, need a 75/1200 baud serial connection to connect to the tranceiver, it doesn't help that USB or Firewire is much faster. And where do you find a 75/1200 serial connector card for a PC? And how's your PC's EBCDIC character set support, for that matter?
      If you have to design both the hardware and the software, it's going to be expensive. Not to say untested. And with the probes being where they are, it's not like you get a second chance if there's a bug. Things have to work perfectly, every time. You'd have a hard time convincing anyone that your emulation would be perfect enough to replace something that's aced the test of time for 25 years.

    4. Re:I've got an old dell they can use... by Zarhan · · Score: 4, Insightful

      Anyone know if the Voyagers rely on a heartbeat or something? If it's just a receiver I can't see why building a modern backup isn't worthwhile.

      They do. First, take a look at

      http://voyager.jpl.nasa.gov/mission/weekly-reports /index.htm

      Namely (of the latest one):

      Voyager 1 command operations consisted of the uplink of a command loss timer reset on 08/04 [DOY 216/0135z] and CCSL A064 on 08/06 [DOY 218/0236z]. The spacecraft received all commands sent and the CCSL was verified.

      Voyager 2 command operations consisted of the uplink of a TLMPRG and a command loss timer reset on 08/06 [DOY 218/1329z]. The spacecraft received all commands sent and the Telemetry Purge proceeded nominally per predicts.

      So yeah, they are still uplinking stuff - mostly just command loss timer resets.

      What happens if they don't send the timer reset? Well, see

      http://voyager.jpl.nasa.gov/science/thirty.html

      If the timer reaches zero, as a result of a command not being received by the spacecraft within the programmed six week duration, the command loss timer will have expired and the Command Loss (CMDLOS) routine will be activated which leads to the initiation of the BML.

      The implementation of BML-7 (the seventh BML to be loaded on-board Voyager 2), in conjunction with the baseline sequence, provides this automated protection against loss of command capability. BML-7, with some differences in implementation for the two spacecraft, is loaded on-board both Voyager 1 and 2.

      So yeah, if receiver on V-ger gets broken, or the transmitter down here on earth, the ship can continue to still send data down here in a completely autonomous fashion. However, a remote capability is probably a good idea to have if something interesting comes up.

      (The link has more details what the "BML" entails).

    5. Re:I've got an old dell they can use... by mrmeval · · Score: 4, Insightful

      You are stepping into the twilight zone of the military industrial complex/government procurement system.

      An existing system that works has gone through the bowels of this system and been sanctified.

      It would take as much money to re-engineer it as it does to maintain it. It is an annoying fact that getting money to fix something in either the military or government is easier than getting something new even if the new item would save money. This is one of the reasons several of the systems I've worked on were 20+ years old. The anti-mortar Firefinder radar being used in Iraq was designed in the seventies and finally approved and deployed in the 80s and is still in use today.

      There are plans to replace it but right this instant they need them in the field so it costs much more to refurbish one than to buy either a 'newly' made one which is intended for foreign sales and is not authorized for procurement or procure the newest model.

      Currently the latest and greatest is rumbling around the guts of the system and some prototypes were fielded in 1998 so expect them to be finalized in 2008 and accepted later....

      I wish I could point and say "graft and corruption" but it's fighting that which has led to our current procurement system. It's not ever going to be perfect but it does help to keep sawdust out of MREs.

      --
      I'd go on a Vegan diet but the delivery time from Vega is too long. --brownkitty
    6. Re:I've got an old dell they can use... by PetraData · · Score: 2, Insightful

      This assumes that:

      (a) they have the source code
      (b) the source code is not too obfuscated from 1970s engineering paradigms that it can be understood
      (c) the guy who originally wrote the system is not dead so that they can talk to him about all the eccentricities of it
      (d) that it isn't too bulky to cause a slowdown on NASA's emulators when dealing with real time communication
      (e) there is no funky encryption built into the system to protect it from the Soviets

      In terms of cost/benefit analysis, it's probably just cheaper for them to leave the old equipment running than pay millions for consultants to take a look at how to port a 1970s communication system built at the height of the Cold War ... to Windows.

    7. Re:I've got an old dell they can use... by Pseudonym · · Score: 3, Insightful

      And where do you find a 75/1200 serial connector card for a PC?

      Give me a week and a modern microcontroller and I'll build you one. Someone else can write the driver.

      --
      sub f{($f)=@_;print"$f(q{$f});";}f(q{sub f{($f)=@_;print"$f(q{$f});";}f});
    8. Re:I've got an old dell they can use... by Kjella · · Score: 2, Insightful

      So yeah, they are still uplinking stuff - mostly just command loss timer resets.

      And there's the #1 reason not to touch this system already. Both probes have left the solar system and entered interstellar space. There's something like ~70000 years to the next star system. We're not expecting them to find anything, and if they did the direction they're going is probably as good as any. Right now it's just the record for "most distant object we've held communication with", so don't mess with it. Is it seriously that big a problem to keep the system going here on earth when you manage to keep it going in outer space? Ir's not like we need to upgrade it for any reason, it's basicly living its own life together with the Voyager probes, like a small bubble of the 70s. Worst case the hardware completely breaks down with no spares and we have to just listen to it, which is what we do already (I assume we can do that with more modern equipment). So where's the upside of moving to a newer system?

      --
      Live today, because you never know what tomorrow brings
    9. Re:I've got an old dell they can use... by nurb432 · · Score: 2, Insightful

      Ok, so run them in parallel for 10 years. Its not like there is a hurry here.

      And since you seem to hik we cant create 'new', what happens when one of the old ones die and we cant repair it due to its age? At least if we have tried to replicate the functions with modern equipment we have a chance.

      Cost is relative, in this case.

      --
      ---- Booth was a patriot ----
    10. Re:I've got an old dell they can use... by FinestLittleSpace · · Score: 2, Insightful

      I always thought it was the Voyager 'probe', not satellitte. Satellitte suggests 'orbit'.

    11. Re:I've got an old dell they can use... by jafiwam · · Score: 4, Insightful

      If I recall correctly, there are several actual science projects still going on with these two spacecraft, despite most of the instruments not being relevant for the tasks, technicians have found ways to tease extra information out of them.

      First, the heliopause / helioshock transition did not happen the way they thought it did. It was in a different place and had different characteristics. They may still run into that, including vibration and change "bell ringing" of it. And, these things might be the only chance we EVER get to study the interstellar medium directly.

      Second, there are light speed, distances vs. gravitiy issues where the spacecraft are NOT WHERE WE EXPECT THEM TO BE based on the equations we have to calculate for that. In other words, basic, fundamental cosmological questions can be pondered using these things.

      The shame is, that people have been trying to turn them off thinking "we're done" when the cost to operate is a freaking drop in the bucket compared to the colossal waste that is the space shuttle. Put down your trashy science fiction novels for once and read some real papers produced by real science. Then you can get outside your narrow view of what one can "find" out there.

    12. Re:I've got an old dell they can use... by jlarocco · · Score: 2, Insightful

      It blows my mind that smart people think things have to be "purchased" they do not. build them. you have the specifications. and I bet that someone has a EBCDIC set for linux out there already.

      They *already* built the system. They already have a staff capable of maintaining it and fixing it when it breaks. Building a new one won't let them communicate with the probes any faster.

      So what would be the purpose of building a completely new one?

      It blows my mind that nobody seems to understand upgrading "just because" is a really stupid idea.

      --
      Maybe not
    13. Re:I've got an old dell they can use... by wazoox · · Score: 4, Insightful

      This is exactly how broken 78RPMs records are read today, mostly old radio archives. The sound can even be better than actually reading the disk on a real phono :)

    14. Re:I've got an old dell they can use... by spaceyhackerlady · · Score: 2, Insightful

      it's going to be expensive. Not to say untested. And with the probes being where they are, it's not like you get a second chance if there's a bug. Things have to work perfectly, every time. You'd have a hard time convincing anyone that your emulation would be perfect enough to replace something that's aced the test of time for 25 years.

      Isn't that always the case? Yes, the system could be rewritten, if there was time and money to do so. Yes, the old hardware could be emulated, as-is, in new hardware. But the old hardware's bugs are known, are understood, and may even have become part of the de facto specification.

      Under the circumstances, I'd nurse the old hardware along too.

      ...laura

  2. Cost benefit analysis by Colin+Smith · · Score: 2, Insightful

    Seems like nobody's done one for the costs of hiring a couple of engineers to reverse engineer or re-implement the protocol...

    --
    Deleted
    1. Re:Cost benefit analysis by arth1 · · Score: 2, Insightful

      More likely, they have done just that, which is exactly why this runs on legacy hardware and software.

      (The definition of legacy is "something that works".)

  3. Its probably the different pots of money question. by Thanster · · Score: 2, Insightful

    In (my experience of) public finances, an expenditure to re implement a protocol would be a capital expense, bring on "careful" scrutiny of the whole programme, and risk all these scientists jobs etc. (with no guarantee of getting the cash) and given that the question being answered is more than an entire career in the making (wall clock wise)......... A maintaince bill for existing equipment gets paid (almost) no questions asked.......

  4. Re:What about this requires old equipment? by Detritus · · Score: 3, Insightful

    The reporter is clueless. It's all a matter of money. It's very expensive to take an old piece of software, written in some obscure language, running on an old machine with a weird architecture, reverse engineer the requirements, rewrite it for a modern machine, and debug and test it thoroughly. You need people who understand the old system and the environment that it ran in. It's usually much cheaper to keep the old hardware running. Plus, many older systems were custom designs, optimized for a particular task, and can still do a better job than more generic modern hardware.

    --
    Mea navis aericumbens anguillis abundat
  5. it's cheaper, this way. by Anonymous Coward · · Score: 1, Insightful

    reanalyze and redesign the whole system, even with the goal of emulating it on current hardware, would cost a fortune.

    i think it's safer and cheaper to leave it alive...

    for younger folks thinking about emulating it on an off the shelf machine: current architectures and hardware are not always "better"; space exploration aside, for certain goals it's simpler to use a '70 thing working a custom tailored board than a oh-shi...-look-at-that-latency-its-impredictable!- harware...

    6502s and z80s are still manifactured, indeed.

  6. The original equipment probabily just works... by Anonymous Coward · · Score: 5, Insightful

    Communication with different equipment has been done. http://www.arrl.org/news/stories/2006/04/25/2/

    Proof that it's not a problem to receive and decode. Transmit can't be any harder. But why "upgrade" it if they don't have to? The old equipment probably works just fine, so there is no incentive.

  7. Re:What about this requires old equipment? by jamesh · · Score: 3, Insightful

    Ok, here is an idea then.. open source. Yes, there are thousands of geeks out there who, if the protocol was simply published, would write that software for the pure pleasure of it.

    Failing that, you'd put the software under the DMCA and claim that it was the hd-dvd encryption algorithm. You'd have three different OSS solutions in a week.
  8. They have the source code and the architecture by Qbertino · · Score: 3, Insightful

    The reprogrammed Voyager 2 to send color pictures while it had been en route for 15 years allready. Mind you, they reprogrammed Voyager 2 to send *color pictures* made with a system that was built to make b/w pictures. Using a single digit amount of registers to push single bits around a 30 year old computer that has less oomph than todays cheapest calculators aboard a space probe that is a kazillion-billion miles away is quite a stunt. Let alone updating the OS this way to generate color images.

    I think these guys know what they are doing and if they choose to keep the old equipment running in order to communicate more relyably with the Voyagers, I trust they have perfectly valid reasons for it. And no, an off-the-shelf Dell is most probably not a feasable replacement. No matter how powerfull it is.

    Oh, and by the way: A modern computer would drain voyagers batteries so fast, they'd be dead in a few hours. My old Sharp 1403 H Pocket Computer, built with technology from the early-to-mid 80s runs 200+ hours under full load on a pair of button-cells. I haven't replaced them in 10 years and it still runs on them. I have yet to find a modern handheld computer that can do this.

    --
    We suffer more in our imagination than in reality. - Seneca
    1. Re:They have the source code and the architecture by InvalidError · · Score: 4, Insightful

      Oh, and by the way: A modern computer would drain voyagers batteries so fast, they'd be dead in a few hours. Never mind that Dell's on-site technical support service is currently not offered in extra-solar-system locations.

      Most people here are talking about upgrading the base station on Earth, not the spacecrafts. As someone else pointed out, most of the reason they are sticking with the old system must be quirky analog/RF components, not the bitstreams themselves - the Voyager base-station antenna is a huge dish array that recovers sub-yoctowatt signals from the probes. The analog/RF front-end needed to filter and amplify this signal before it can be decoded by digital equipment must be a very unique piece of analog kit with decades worth of tweaking and refinement poured into it both before and after the launch.

      The digital decoding should be trivial with modern CPUs but the analog parts were most likely tuned to the point of defying modern technology.
    2. Re:They have the source code and the architecture by Lumpy · · Score: 2, Insightful

      The funny part is the TTL power hogs of yesteryore have a better chance of dealing with space radiation than the new stuff. The full 5V swing between logic levels, and some of the older 70's computing that did a full 10V swing from +5 to -5 volts makes the current stuff seem like unstable messes when exposed to radiation. It is probably one of the reasons those great giant science projects from the beginning of the space race still work.

      Granted, we still have some amazing engineers, the two rovers on mars are proof of that.

      I think the funny part is that most people do not realize how incredibly big that voyagers are. 733Kg is HUGE for a space probe. The thing is nearly the size of a City BUS, and it actually has 420Watts of power from it's power source giving it an incredible amount of electrical power on board. the things were massive, but back then a basic computer with less processing power than my watch took up a toolbox, so it makes sense.

      honestly I am sad that they havent done any follow up deep space probes with an ion engine to get them going on insanely fast (compared to the other probes) trip on out. it would be cool to see a photo of Pluto or some oort cloud objects.

      --
      Do not look at laser with remaining good eye.
  9. outmoded? by timmarhy · · Score: 2, Insightful
    Sounded a lot like penis envy to me. Those engineers in the 70's knew what they were doing, unlike the kids today who breeze past their competency based exams.

    The voyager sats are some of our most successful missions, i'd challenge anyone to do better then their "out modded" systems.

    --
    If you mod me down, I will become more powerful than you can imagine....
  10. Re:What about this requires old equipment? by Detritus · · Score: 2, Insightful

    You underestimate how much a clever programmer can do with 4kw (kiloword) on many of these systems. These programs can be very complex and difficult to understand, even with the source code.

    --
    Mea navis aericumbens anguillis abundat
  11. "Why can't they just" by DynaSoar · · Score: 3, Insightful

    When someone says "Why don't they just", it usually means they have no idea how it's being done, and is just taking that opportunity to show what they know, even though they have no idea if it's applicable.

    When someone says "Why don't we just", they're probably working on the project and know what they're talking about.

    If they could just, they probably would have justed a long time ago. These are, after all, the people who rebuilt the receiver scheduled to receive the Apollo 11 LEM and EVA transmissions in just 12 hours, after it caught fire 1 day into the mission. It was NASA's call not to use them due to the problem, but they could have done it because they know very well what they're doing and how to do it.

    --
    "I may be synthetic, but I'm not stupid." -- Bishop 341-B